Abstract: The ultrasonic-assisted aqueous enzymatic extraction technology was used to extract oil from paeonia seeds. Based on Box-Benhnken central combination design,effects of three crucial factors(ultrasonic power,ultrasonic temperature and extraction time) on extraction yield of peony oil were investigated by response surface analysis. The optimal technological condition of oil extraction was determined as follows:the ultrasonic power was 400 W,the ultrasonic temperature was 40 ℃ and the extraction time was 45 min. Under such condition,the total oil extraction rate was 2.02%±0.05%. Compared the ultrasonic assisted aqueous enzymatic oil extraction(extraction rate 22.13%) with directly enzymatic hydrolysis(extraction rate 20.34%) and solvothermal method(extraction rate 24.58%),the result indicated that ultrasonic assisted method could enhance the extraction efficiency,reduce the free fatty acid and low the acid value,therefore the oil property could be improved.